struct Rectangle{
    width:u32,
    height:u32,
}

enum Direction {
    Up,
    Down,
    Left,
    Right,
}


fn main() {
    println!("Hello, world!");
    let rect=Rectangle{
        width:10,
        height:30,
    };
    // 添加一些改动在main函数里面

let direction=Direction::Up;

}
